My wife got my Blazer when I got a newer work truck. After about a month or so it started losing coolant with no drips/puddles visible anywhere. So everyone I talked to about it instantly said LIM. GREAT like I have the time or cash for THAT job, so I kept putting it off. She was only adding about 1/2 gal a week or so I figured she can live with it for now.

3 weeks ago it started dripping from the front of the engine. Swapped the water pump and now there is NO coolant loss in over 2 weeks!

Moral of the story.....Don't jump to LIM for slow coolant loss with no visible signs of where it's going!

 

True that, and the water pump is about the easiest thing to change.

 

That's the importance of a cooling system pressure test. If there's an external leak, you'll see it.